Reconstructions of KP/SPM (orange) and SoHO/MDI (blue) for the overlap period May 1996 to September 2003; KP/SPM is normalised to MDI after February 1999. Daily data are shown as thin lines, smoothed as thick, with the grey boxes covering periods when SoHO was out of contact. Prior to the loss of contact, MDI is also plotted shifted by a constant value (daily data, black thin solid line; smoothed, dashed thick line).